This invention relates to a trailer gooseneck apparatus and particularly for interconnecting of a low-boy trailer to a truck tractor.
Commercial trucking includes semitrailer systems wherein a truck tractor is releasably coupled to a trailing load carrying trailer for over the road transport of loads. A low-boy trailer is widely used for transport of off-road construction equipment, such as graders, shovels and the like. The trailer has a flat bed supported at the trailing end by one or more sets of tired wheel supports. A gooseneck apparatus releasably connects the free forward end of the flat bed to the tractor for over-the-road movement.
A particularly satisfactory gooseneck apparatus is shown in applicant's copending application entitled "Trailer Gooseneck Apparatus" which was filed Dec. 16, 1980 with Ser. No. 06/217,050 now issued to U.S. Pat. No. 4,390,192 on June 23, 1983. The gooseneck apparatus includes a horizontal section having a releasable pivot connector for connection to a truck-tractor and a vertical section including a unique releasable entrance support and connection assembly with the trailer. The vertical section is pivotally interconnected at its forward or tractor end to the understructure of the horizontal section and extends rearwardly beneath the horizontal section. The trailer ends of the horizontal section rests upon the vertical section and the sections are interconnected by a powered actuating means such as hydraulic cylinder units pivotally interconnected to two sections. The lower end of the vertical section is coupled to the low-boy trailer by a combination of horizontal and vertical pin-like connections. A horizontally extended pin and slot connection provides a vertical support with releasable interconnection of the trailer to the tractor. A vertical pin and slot coupling allows corresponding connection of the trailer to the vertical section of the gooseneck. A pivotally mounted load structure, preferably in the form of a plate in the vertical section, is movable with respect to the horizontal section to establish a collapse of the vertical section during the attachment and detachment of the trailer without requiring relative motion between the truck tractor and the trailer bed. The attachment and detachment is established without relative movement between the trailer bed and the tractor.
A simple and reliable coupling includes a pneumatic operated coupling pin interconnected to pin opening connection. The trailer includes a coupling opening which is aligned with a mating coupling pin. A spring return means urges the pin into the coupling position. The pneumatic unit is actuated to withdraw the pin from the vertical opening.
Although the above gooseneck apparatus has been found to provide a highly effective and reliable connection, some concern may arise with respect to the reliability of the trailer connection if proper care is exercised in operating the system or constructing the apparatus. Thus a possible separation may arise if the coupling pin is not properly set or if the pin should retract against because the spring load provided is not proper for particular harsh road conditions. Although heavy spring loading may be provided, this requires a corresponding larger releasable motor means.